Intermediate Java(13)- frequency, disjoint

import java.util.*;

public class apples{

public static void main(String[] args){

//create an array and convert to list

String[] stuff = {"bird","mouse","fish","dog"};

List<String> list1 = Arrays.asList(stuff);

ArrayList<String> list2 = new ArrayList<String>();

list2.add("youtube");

list2.add("google");

list2.add("digg");

for(String x:list2)

System.out.printf("%s ",x);

Collections.addAll(list2, stuff); → 將stuff所有的內容加到list2

System.out.println();

for(String x:list2)

System.out.printf("%s ",x);

System.out.println();

System.out.println(Collections.frequency(list2, "digg")); → 出現多少次digg

boolean tof = Collections.disjoint(list1, list2); → list1同2是不是沒有共同之處

System.out.println(tof);

if(tof)

System.out.println("these list does not have anything in common");

else

System.out.println("these list must have something in common");

}

}

這是運行時的結果:

 youtube google digg

youtube google digg bird mouse fish dog

1

false

these list must have something in common